Hang on a second. We don't have a good way to test an ICM and it'* the most expensive part. We should always refrain from shotgunning suggestions at folks when we don't have the experience of ICM'* typically going bad.
Our exsperience on this forum is that crank sensors go bad often enough and that ICM'* typically don't. In the past couple years, we've seen maybe 2 bad ICM'* and one was recent (symptoms were no spark on one coil), we've seem probably 2-3 crank sensors each month. DanThurs found a nicked wire after a cam install.
We should ask, has any work been done to the car in the recent couple of months before this started to happen?
Dan.. do you have the wiring diagram or instructions handy to test the wiring from crank/cam sensors up to the ICM?
00 Regal GS: All kinds of cool stuff.